Computer networks are collections of hardware and software that connect computers and allow them to send information from one computer to another electronically. A computer network is comprised of the physical hardware connections between the various computers, for example telephone lines, coax cable or fiber optic cable, and the software used to send and receive data and to route the data to the selected computer on the network.
A local area network (LAN) is a network connection between computers in close proximity, typically less than one mile. A wide area network (WAN) is a network of computers located at longer distances, often connected by telephone lines, dedicated long-range communication lines, or satellite links. The Internet is an example of a very large wide area network. Network software may sometimes be used with both types of networks.
When a network is fast growing, that is, network elements or nodes are being added frequently, a network administrator may not know all of the nodes connected to the network. Also, a network administrator new to his or her job may not be familiar with the nodes on the network. Determining the nodes manually is a difficult problem. The administrator may contact all the users of the network known to the administrator, however, infrequent users may be forgotten and not contacted. Also, if a node is connected to the network, but not active because the computer is not powered up or is inoperative, that node may not be included in the list. In a very short local area network, a network administrator may physically trace the cable of the network to determine which nodes are located on the network. However, since longer local area networks can extend over a mile, through many floors and offices within a building, physical tracing may be impossible. In a wide area network, physical tracing is almost always impossible.
For some commonly used networks, special equipment can be purchased that will determine the nodes located on the network and the distance between them. This equipment, called a probe, is often limited by the other components of the network, however. For example, in a local area network, a repeater unit may be used to extend the effective distance of the local area network to a distance greater than is capable with a single cable. A repeater unit amplifies signals, and therefore might not allow a probe to determine the location of nodes beyond the repeater.
Other units connected to the network may obscure nodes. For example a bridge unit connects two similar networks but only passes messages that are being sent from a node on one side of the bridge to a node on the other side of the bridge. It will not pass messages between nodes on the same side, in order to reduce the traffic on the other side of the bridge. A bridge will prevent a probe from determining the nodes on the other side of the bridge. A gateway is a unit that connects dissimilar networks to pass messages. Because a gateway may have to reformat a message to accommodate a different network protocol, it might prevent a probe from finding nodes beyond the gateway.
One problem with determining the nodes of a network is that when the network is large, polling all the nodes is very time consuming. Furthermore, to keep an accurate description of all the nodes and the configuration of each node requires that the nodes be polled frequently, thus polling efficiencies are important
There is need in the art then for a method of polling the nodes on a network. There is further need in the art for efficiently polling such nodes. The present invention meets these and other needs in the art.